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1 | #include <linux/capability.h> | |
2 | #include <linux/fs.h> | |
3 | #include <linux/posix_acl.h> | |
4 | #include "reiserfs.h" | |
5 | #include <linux/errno.h> | |
6 | #include <linux/pagemap.h> | |
7 | #include <linux/xattr.h> | |
8 | #include <linux/slab.h> | |
9 | #include <linux/posix_acl_xattr.h> | |
10 | #include "xattr.h" | |
11 | #include "acl.h" | |
12 | #include <linux/uaccess.h> | |
13 | ||
14 | static int __reiserfs_set_acl(struct reiserfs_transaction_handle *th, | |
15 | struct inode *inode, int type, | |
16 | struct posix_acl *acl); | |
17 | ||
18 | ||
19 | int | |
20 | reiserfs_set_acl(struct inode *inode, struct posix_acl *acl, int type) | |
21 | { | |
22 | int error, error2; | |
23 | struct reiserfs_transaction_handle th; | |
24 | size_t jcreate_blocks; | |
25 | int size = acl ? posix_acl_xattr_size(acl->a_count) : 0; | |
26 | ||
27 | ||
28 | /* | |
29 | * Pessimism: We can't assume that anything from the xattr root up | |
30 | * has been created. | |
31 | */ | |
32 | ||
33 | jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) + | |
34 | reiserfs_xattr_nblocks(inode, size) * 2; | |
35 | ||
36 | reiserfs_write_lock(inode->i_sb); | |
37 | error = journal_begin(&th, inode->i_sb, jcreate_blocks); | |
38 | reiserfs_write_unlock(inode->i_sb); | |
39 | if (error == 0) { | |
40 | error = __reiserfs_set_acl(&th, inode, type, acl); | |
41 | reiserfs_write_lock(inode->i_sb); | |
42 | error2 = journal_end(&th); | |
43 | reiserfs_write_unlock(inode->i_sb); | |
44 | if (error2) | |
45 | error = error2; | |
46 | } | |
47 | ||
48 | return error; | |
49 | } | |
50 | ||
51 | /* | |
52 | * Convert from filesystem to in-memory representation. | |
53 | */ | |
54 | static struct posix_acl *reiserfs_posix_acl_from_disk(const void *value, size_t size) | |
55 | { | |
56 | const char *end = (char *)value + size; | |
57 | int n, count; | |
58 | struct posix_acl *acl; | |
59 | ||
60 | if (!value) | |
61 | return NULL; | |
62 | if (size < sizeof(reiserfs_acl_header)) | |
63 | return ERR_PTR(-EINVAL); | |
64 | if (((reiserfs_acl_header *) value)->a_version != | |
65 | cpu_to_le32(REISERFS_ACL_VERSION)) | |
66 | return ERR_PTR(-EINVAL); | |
67 | value = (char *)value + sizeof(reiserfs_acl_header); | |
68 | count = reiserfs_acl_count(size); | |
69 | if (count < 0) | |
70 | return ERR_PTR(-EINVAL); | |
71 | if (count == 0) | |
72 | return NULL; | |
73 | acl = posix_acl_alloc(count, GFP_NOFS); | |
74 | if (!acl) | |
75 | return ERR_PTR(-ENOMEM); | |
76 | for (n = 0; n < count; n++) { | |
77 | reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value; | |
78 | if ((char *)value + sizeof(reiserfs_acl_entry_short) > end) | |
79 | goto fail; | |
80 | acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag); | |
81 | acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm); | |
82 | switch (acl->a_entries[n].e_tag) { | |
83 | case ACL_USER_OBJ: | |
84 | case ACL_GROUP_OBJ: | |
85 | case ACL_MASK: | |
86 | case ACL_OTHER: | |
87 | value = (char *)value + | |
88 | sizeof(reiserfs_acl_entry_short); | |
89 | break; | |
90 | ||
91 | case ACL_USER: | |
92 | value = (char *)value + sizeof(reiserfs_acl_entry); | |
93 | if ((char *)value > end) | |
94 | goto fail; | |
95 | acl->a_entries[n].e_uid = | |
96 | make_kuid(&init_user_ns, | |
97 | le32_to_cpu(entry->e_id)); | |
98 | break; | |
99 | case ACL_GROUP: | |
100 | value = (char *)value + sizeof(reiserfs_acl_entry); | |
101 | if ((char *)value > end) | |
102 | goto fail; | |
103 | acl->a_entries[n].e_gid = | |
104 | make_kgid(&init_user_ns, | |
105 | le32_to_cpu(entry->e_id)); | |
106 | break; | |
107 | ||
108 | default: | |
109 | goto fail; | |
110 | } | |
111 | } | |
112 | if (value != end) | |
113 | goto fail; | |
114 | return acl; | |
115 | ||
116 | fail: | |
117 | posix_acl_release(acl); | |
118 | return ERR_PTR(-EINVAL); | |
119 | } | |
120 | ||
121 | /* | |
122 | * Convert from in-memory to filesystem representation. | |
123 | */ | |
124 | static void *reiserfs_posix_acl_to_disk(const struct posix_acl *acl, size_t * size) | |
125 | { | |
126 | reiserfs_acl_header *ext_acl; | |
127 | char *e; | |
128 | int n; | |
129 | ||
130 | *size = reiserfs_acl_size(acl->a_count); | |
131 | ext_acl = kmalloc(sizeof(reiserfs_acl_header) + | |
132 | acl->a_count * | |
133 | sizeof(reiserfs_acl_entry), | |
134 | GFP_NOFS); | |
135 | if (!ext_acl) | |
136 | return ERR_PTR(-ENOMEM); | |
137 | ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION); | |
138 | e = (char *)ext_acl + sizeof(reiserfs_acl_header); | |
139 | for (n = 0; n < acl->a_count; n++) { | |
140 | const struct posix_acl_entry *acl_e = &acl->a_entries[n]; | |
141 | reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e; | |
142 | entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag); | |
143 | entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm); | |
144 | switch (acl->a_entries[n].e_tag) { | |
145 | case ACL_USER: | |
146 | entry->e_id = cpu_to_le32( | |
147 | from_kuid(&init_user_ns, acl_e->e_uid)); | |
148 | e += sizeof(reiserfs_acl_entry); | |
149 | break; | |
150 | case ACL_GROUP: | |
151 | entry->e_id = cpu_to_le32( | |
152 | from_kgid(&init_user_ns, acl_e->e_gid)); | |
153 | e += sizeof(reiserfs_acl_entry); | |
154 | break; | |
155 | ||
156 | case ACL_USER_OBJ: | |
157 | case ACL_GROUP_OBJ: | |
158 | case ACL_MASK: | |
159 | case ACL_OTHER: | |
160 | e += sizeof(reiserfs_acl_entry_short); | |
161 | break; | |
162 | ||
163 | default: | |
164 | goto fail; | |
165 | } | |
166 | } | |
167 | return (char *)ext_acl; | |
168 | ||
169 | fail: | |
170 | kfree(ext_acl); | |
171 | return ERR_PTR(-EINVAL); | |
172 | } | |
173 | ||
174 | /* | |
175 | * Inode operation get_posix_acl(). | |
176 | * | |
177 | * inode->i_mutex: down | |
178 | * BKL held [before 2.5.x] | |
179 | */ | |
180 | struct posix_acl *reiserfs_get_acl(struct inode *inode, int type) | |
181 | { | |
182 | char *name, *value; | |
183 | struct posix_acl *acl; | |
184 | int size; | |
185 | int retval; | |
186 | ||
187 | switch (type) { | |
188 | case ACL_TYPE_ACCESS: | |
189 | name = XATTR_NAME_POSIX_ACL_ACCESS; | |
190 | break; | |
191 | case ACL_TYPE_DEFAULT: | |
192 | name = XATTR_NAME_POSIX_ACL_DEFAULT; | |
193 | break; | |
194 | default: | |
195 | BUG(); | |
196 | } | |
197 | ||
198 | size = reiserfs_xattr_get(inode, name, NULL, 0); | |
199 | if (size < 0) { | |
200 | if (size == -ENODATA || size == -ENOSYS) | |
201 | return NULL; | |
202 | return ERR_PTR(size); | |
203 | } | |
204 | ||
205 | value = kmalloc(size, GFP_NOFS); | |
206 | if (!value) | |
207 | return ERR_PTR(-ENOMEM); | |
208 | ||
209 | retval = reiserfs_xattr_get(inode, name, value, size); | |
210 | if (retval == -ENODATA || retval == -ENOSYS) { | |
211 | /* | |
212 | * This shouldn't actually happen as it should have | |
213 | * been caught above.. but just in case | |
214 | */ | |
215 | acl = NULL; | |
216 | } else if (retval < 0) { | |
217 | acl = ERR_PTR(retval); | |
218 | } else { | |
219 | acl = reiserfs_posix_acl_from_disk(value, retval); | |
220 | } | |
221 | ||
222 | kfree(value); | |
223 | return acl; | |
224 | } | |
225 | ||
226 | /* | |
227 | * Inode operation set_posix_acl(). | |
228 | * | |
229 | * inode->i_mutex: down | |
230 | * BKL held [before 2.5.x] | |
231 | */ | |
232 | static int | |
233 | __reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode, | |
234 | int type, struct posix_acl *acl) | |
235 | { | |
236 | char *name; | |
237 | void *value = NULL; | |
238 | size_t size = 0; | |
239 | int error; | |
240 | ||
241 | switch (type) { | |
242 | case ACL_TYPE_ACCESS: | |
243 | name = XATTR_NAME_POSIX_ACL_ACCESS; | |
244 | if (acl) { | |
245 | error = posix_acl_update_mode(inode, &inode->i_mode, &acl); | |
246 | if (error) | |
247 | return error; | |
248 | } | |
249 | break; | |
250 | case ACL_TYPE_DEFAULT: | |
251 | name = XATTR_NAME_POSIX_ACL_DEFAULT; | |
252 | if (!S_ISDIR(inode->i_mode)) | |
253 | return acl ? -EACCES : 0; | |
254 | break; | |
255 | default: | |
256 | return -EINVAL; | |
257 | } | |
258 | ||
259 | if (acl) { | |
260 | value = reiserfs_posix_acl_to_disk(acl, &size); | |
261 | if (IS_ERR(value)) | |
262 | return (int)PTR_ERR(value); | |
263 | } | |
264 | ||
265 | error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0); | |
266 | ||
267 | /* | |
268 | * Ensure that the inode gets dirtied if we're only using | |
269 | * the mode bits and an old ACL didn't exist. We don't need | |
270 | * to check if the inode is hashed here since we won't get | |
271 | * called by reiserfs_inherit_default_acl(). | |
272 | */ | |
273 | if (error == -ENODATA) { | |
274 | error = 0; | |
275 | if (type == ACL_TYPE_ACCESS) { | |
276 | inode->i_ctime = current_time(inode); | |
277 | mark_inode_dirty(inode); | |
278 | } | |
279 | } | |
280 | ||
281 | kfree(value); | |
282 | ||
283 | if (!error) | |
284 | set_cached_acl(inode, type, acl); | |
285 | ||
286 | return error; | |
287 | } | |
288 | ||
289 | /* | |
290 | * dir->i_mutex: locked, | |
291 | * inode is new and not released into the wild yet | |
292 | */ | |
293 | int | |
294 | reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th, | |
295 | struct inode *dir, struct dentry *dentry, | |
296 | struct inode *inode) | |
297 | { | |
298 | struct posix_acl *default_acl, *acl; | |
299 | int err = 0; | |
300 | ||
301 | /* ACLs only get applied to files and directories */ | |
302 | if (S_ISLNK(inode->i_mode)) | |
303 | return 0; | |
304 | ||
305 | /* | |
306 | * ACLs can only be used on "new" objects, so if it's an old object | |
307 | * there is nothing to inherit from | |
308 | */ | |
309 | if (get_inode_sd_version(dir) == STAT_DATA_V1) | |
310 | goto apply_umask; | |
311 | ||
312 | /* | |
313 | * Don't apply ACLs to objects in the .reiserfs_priv tree.. This | |
314 | * would be useless since permissions are ignored, and a pain because | |
315 | * it introduces locking cycles | |
316 | */ | |
317 | if (IS_PRIVATE(dir)) { | |
318 | inode->i_flags |= S_PRIVATE; | |
319 | goto apply_umask; | |
320 | } | |
321 | ||
322 | err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); | |
323 | if (err) | |
324 | return err; | |
325 | ||
326 | if (default_acl) { | |
327 | err = __reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT, | |
328 | default_acl); | |
329 | posix_acl_release(default_acl); | |
330 | } | |
331 | if (acl) { | |
332 | if (!err) | |
333 | err = __reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS, | |
334 | acl); | |
335 | posix_acl_release(acl); | |
336 | } | |
337 | ||
338 | return err; | |
339 | ||
340 | apply_umask: | |
341 | /* no ACL, apply umask */ | |
342 | inode->i_mode &= ~current_umask(); | |
343 | return err; | |
344 | } | |
345 | ||
346 | /* This is used to cache the default acl before a new object is created. | |
347 | * The biggest reason for this is to get an idea of how many blocks will | |
348 | * actually be required for the create operation if we must inherit an ACL. | |
349 | * An ACL write can add up to 3 object creations and an additional file write | |
350 | * so we'd prefer not to reserve that many blocks in the journal if we can. | |
351 | * It also has the advantage of not loading the ACL with a transaction open, | |
352 | * this may seem silly, but if the owner of the directory is doing the | |
353 | * creation, the ACL may not be loaded since the permissions wouldn't require | |
354 | * it. | |
355 | * We return the number of blocks required for the transaction. | |
356 | */ | |
357 | int reiserfs_cache_default_acl(struct inode *inode) | |
358 | { | |
359 | struct posix_acl *acl; | |
360 | int nblocks = 0; | |
361 | ||
362 | if (IS_PRIVATE(inode)) | |
363 | return 0; | |
364 | ||
365 | acl = get_acl(inode, ACL_TYPE_DEFAULT); | |
366 | ||
367 | if (acl && !IS_ERR(acl)) { | |
368 | int size = reiserfs_acl_size(acl->a_count); | |
369 | ||
370 | /* Other xattrs can be created during inode creation. We don't | |
371 | * want to claim too many blocks, so we check to see if we | |
372 | * we need to create the tree to the xattrs, and then we | |
373 | * just want two files. */ | |
374 | nblocks = reiserfs_xattr_jcreate_nblocks(inode); | |
375 | nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb); | |
376 | ||
377 | REISERFS_I(inode)->i_flags |= i_has_xattr_dir; | |
378 | ||
379 | /* We need to account for writes + bitmaps for two files */ | |
380 | nblocks += reiserfs_xattr_nblocks(inode, size) * 4; | |
381 | posix_acl_release(acl); | |
382 | } | |
383 | ||
384 | return nblocks; | |
385 | } | |
386 | ||
387 | /* | |
388 | * Called under i_mutex | |
389 | */ | |
390 | int reiserfs_acl_chmod(struct inode *inode) | |
391 | { | |
392 | if (IS_PRIVATE(inode)) | |
393 | return 0; | |
394 | if (get_inode_sd_version(inode) == STAT_DATA_V1 || | |
395 | !reiserfs_posixacl(inode->i_sb)) | |
396 | return 0; | |
397 | ||
398 | return posix_acl_chmod(inode, inode->i_mode); | |
399 | } |